Stair structure



B. R. BURNHAM STAIR STRUCTURE June 1 192s. 1,5s7,2s1

Filed Sept. 12,'1925 I INVENTOR.

ATTORNEY.

Patented June 1, 1926;

BRANCH; n, BURNH OF WHIT EY, some; CAROLINA.

' ISM-LR STRUCTUR My invention reletee to impr oyements in sta11- structures, and more pe-lfi'tlcul arl y 1n the stringeu's 7 thereof, end eoneists ,e ss entielly of Figure 21 sheet-metal strip eutend hent to fol'flifl stfingef pfovided with jsu pjotnting v end 'attaelnng pzfuftset the ends, enchw lth tread suppog' ts extend ngylnwardl y f rom the front ge portion; and aleojivith rieer Sup- 'Q a as herein or fully scribed. e o

The primary object of my invention, is to pliovitle e simple end inexpensive stringer to be} readily feetenepl in place, and tohave tread'e, and ,rlsers when. d.es1 red, :read11y two etpingers' are used in the lCQilStlll CitiQIl of eeeh flgghtofeteps or stems. The stan' structure: "pyodnced with the bid 1 of "these w n e 1 v r -;rv e' ..d.- durable; and serves every purposeof a sta n etl'uetnye of the 01d type. V V

The stringers .aye punched ont of. fofr ned from ,sheet -nletel, hence ar putatively lightin Weight.

Other O j s n fl veiitage w l we? in the eehrse of the iollo ing .c1eeeription.

I the objects 2311 01 lsec l l ethe ad vantages of my invention vby th e nez x ns illus Whiehfh es been pu nehe d frem ap iece of sheet-metal and out or sht and: oerfinc I inneachness to befolfgmed 111110 21 str lnger emhodying a prectieel 51 1 of lmy insgenme; 2, .a fleet el vation b a we structnl e inqvhich ere ll leQlipolfi lted tx vo of the stringers fopn'led from hlanksflsneh as that shown in the reggdmg View; Fig.

8, atop plan of one ofsei d stringe s'gIFig,

a yerthial section thfongh L Steinstructure showing a eljgh' tlyngodified foninlof stringer, and, (Egg. 5, a ,fnontendielevar tion" of the left-ha-nd ietfinger which be.-

ShnHen reference ehal lc ters d e 'gnete Although Ihzive illustrated in the drawine' flig -steps: havi' 'g' .e thre trends and in-the mod;i;fied;fo 1f1n three nisere in addition, at, 1s to, be underjstooiof eouree,

' t h r may: eta- 1y z ezvs nah fi ml b tread n ise .p evlded; thestnmeexe be made to accommodate the same.

t v- I mecliate wline'12lexte1id is a of a Stit il) orblgnk i p e longs in the strueture illustrated 111 lf g.

Ln thefirstviefivf is shown a stfijoiofblank ll of eheet -tlhetel, provided at the upper end within prdjeetion 2 end mew lower end ith a, .p ro jeqtion 3, end having out inwai'glly" from one longitudinal edge thereof alit' The longjitudihal edgee "of the strip 1fzire 1qafelll with eeeh other. The v bottom edge} fthee tiip 1 kit the" 'rightof theflu'g. 3', would if continuedhe parallel dgge P e Theprojecjtioii 2 inwau gily Qinlthe dot-find-dafsh line 6, whieh line ie 'a' continnition' "of the Lipper'edg'e of the blank tw r a efi lca v supno iti ew e oni'ing lug, oft-flange T 3 hefilppe'r end of the stringer '5, v :The lower ner p ortlon ofrthe blank t g t er with f ee-han we,

' tend-de h' 1 18 to br l .iilb itto n $11? of horizontal V T [numbe nter:

em e fli wh lit andf' i e i Y of the lot'vef slit 4; tlleilpperflil e l2e4tends her.

t ien ll v frolnthe 'outer e ndof'sziid npperls ht Yto the' ang'le fo imed by the: proje etion 2 y'ith the npp er end of thehlank l, the. Short' 1 2,eXtenc1s from-the inner endtof lower Slit 4 to the engleifjorinecl between the blot-- tout and righbhend edges of e aid blank. Ilhelmes 8 andlFZ i f entendedflw ohld e11 berpe l allel with eaeh other. V

'and' 9 the blink lfwhie'h produce the t lf'eag1: su lports 12, and there are also two s h ni lgy openings in the ROlfQlQIl of said strip which is set oil by the doteal ldfila'sh;lines-8 end ll."

I F gthe t e ds-L15 Je T' llQ "mounted -on the tread s uppo rte 13 oflthe tw s r n rs li ei v nea-n ne treads are secured to sand supports by means .thereto by screws, bolts, or other suitable means, to accommodate which the openings 14: are. provided in the part of the blank 1 that'forms said support, such floor or part and fastening means not being shown. The lug 7 at the upper terminal of each stringer rests against a timber or other support of the building structure (not shown), and is secured thereto by means similar to those employed in securing each of the supports 9 in place. The openings 1 4 in the pro ection 2 of the blank 1 are for the accommodation of the aforesaid securing means.

' If desired, a riser (not shown) may be bolted to the lugs 10 through the openings 14 therein.

the treads 15 to their supports.

If it be desired to provide the stair structure with risers, as 19 in Fig. 4, a lip or flange 20 is turned inwardly from the vertical riser portion of each stringer beneath each tread support 13 with wlnch such stringer is provided, except at the bottom where either the lug 10 may be utllized, or in place thereof a lug 21 which will presently be described, and said risers are secured to said flanges and lug by means of screws and nuts similar to those employed to secure There are two openings 14 in each of the flanges 20 and in eitherthe lug 10 or the lug 21 for two of the screws 16. The screws 16 for the risers l9 pass through the latter adjacent to the ends of the same.

In the constructionof the stringer illustrated in Figsd and 5, which stringer is designated by the numeral 5, a narrow horizontal flange 22 is formed on the bottom of said stringer, in place of the larger flange or support 9, andtheriser lug 21 is bent inwardly from the forward end of said stringer, instead of being bent upwardly from the forward end of said larger flange or support. The narrow flange 22 is d signed to be bolted or otherwise secured, like. the support 9, to the floor or other part of the building structure. This base construction of the stringer 5 might be substituted for the base construction of the stringer 5, and vice versa.

Except in the particulars hereinbefore pointed out, the'two stair structures illustrated in connection herewith are generally similar to each other. 7

Obviously some other means besides the screws 16 and nuts 17 may be employed for securing the treads and risers to the stringers.

More or less change in the shape, size, construction, and arrangement of some or all of the parts of this stair structure, in addition to those hereinbefore specifically pointed out, may be made without depart:- ing from thespirit' of my invention or e:- ceeding the scope of what is claimed.

What'I claim as my invention, and desire to secure by Letters Patent, is-

1. In a stair structure, a sheet-metal stringer cut and bent inwardly at one longitudinal edge to form horizontal triangular tread supports, with the base of each of these triangular supports at one end and the apex at the other end, and bent at the lower terminal to form a horizontal base support, said stringer being flat throughout except at said longitudinal edge and the ends.

2. In a stair structure, a sheet-metal stringer cut and bent inwardly at one longitudinal edge to form horizontal triangular tread supports, with the base of each of these triangular supports at one end and the apex at the other end, and bent at the lower terminal to form a horizontal base support which is bent upwardly at the front edge to rovide 'a vertical riser-supporting lug, saic stringer being fiat throughout except at said longitudinal edge and the ends.

3. In a stair structure, a sheet-metal stringer cut and bent inwardly at one longitudinal edge to form horizontal triangular tread supports, with the base of each of these triangular supports at one end and the apex at the other end, bent at the lower terminal to form a horizontal base support which is bent upwardly at the front edge to provide a vertical riser-supporting lug, and bent inwardly at the upper terminal to provide an attaching lug, said stringer being flat throughout except at its longitudinal edge and the ends.

p 4:. In stair structure, a sheet metal stringer strip having both longitudinal edges free and originally parallel with each other. and adapted to be'slit inwardly from one of said edges, the slits being equidistant apart, to have triangular portions of said strip, each defined by one of said slits, an imaginary line between the inner and outer ends of two adjacent slits, and the'intervening part of the longitudinal edge of the strip from which the slits extend inwardly, bent at right-angles to the main portion of the strip, to form tread supports, each triangular portion being bent. on the aforesaid imaginary line.

5. In stair construction, a sheet-metal stringer having both longitudinal edges free and originally parallel with each other and provided with projections at the ends, said strip being adapted to be slit inwardly 1,587,231 it 1 r B from one of saidedges, the slits being equieach: triangular portion being bent on the 10 distant apart, to have triangular portions aforesaid iinaginary line, and to be bent at of said vstrip, each defined by one of said the lower terminal to torni a horizontal base. slits, an in'iaginary linebetween the. inner support, and to have said uppei'projectioii and outenends of two adjacent slits, and the bent inwardly to form an attaching lug and intervening part of the longitudinal edge, of said bottom projection bent, upwardly' to 5 the strip from which the slits extend in form a lug forthe attachment thereto of a Wardly, bent atright-angles to the main riser; s I, i is Z s 7 portion of the strip, to form treadsnpports', BRANCIL R. BURNHAMI 

